Selection for grain yield under normal and deficit irrigation regimes in bread wheat [electronic resource]
الإنتخاب لمحصول الحبوب تحت نظامي الري العادي والري المنخفض في قمح الخبز
- P. 295-306
Includes bibliographic refrence
The objectives of the present research were to study the direct selection response for grain yield planf1 under normal and deficit irrigation conditions and estimate the correlated response of other studied traits. Two cycles of selection were practiced on a segregating populations of wheat cross (Sid 1 x Misr 2) in the F 3-F 5 generations. Selection was practiced separately under normal and deficit irrigation conditions. The genotypic variance was slightly less than the phenotypic variance under both environments and generally decreased from the base population (F 3) to the F 5 generation. Broad-sense heritability estimates for grain yield planf1 after two cycles of selection were 65.66 and 59.95% under normal and deficit irrigation, respectively. The realized heritability under normal irrigation was 47.94 and 53.66% compared to 34.90 and 58.64% under deficit irrigation conditions after the first and second cycles of selection, respectively. The average observed gain for grain yield planf1 from selection under normal and deficit irrigation groups, evaluated under normal irrigation were (13.92 and 15.48%) over the bulk sample and (9.27 and 10.78%) over the better parent, respectively. While, from selection under normal and deficit irrigation, evaluated under deficit irrigation were (16.87 and 20.08%) over the bulk sample and (15.44 and 18.61%) over the better parent, respectively. Drought susceptibility index (DSI) showed that six families selected under normal irrigation and five families selected under deficit irrigation were superior for drought tolerance and had high grain yield under deficit irrigation in F 5 generation. The antagonistic selection was better than the synergistic selection in changing the mean and decreasing the sensitivity.